
(define-structure pt (x y))
(define-structure (3d-pt pt) (z))
(define q (make-3d-pt 7 8 9))
(pt? q)					; => #t
(3d-pt? q)				; => #t
(pt-x q)				; => 7
(3d-pt-z q)				; => 9

(structure->constructor (SinOsc.ar))

;; => (make-ugen 
;;      "SinOsc" 2 
;;      (list (make-constant 440.0 0) (make-constant 0.0 1)) 
;;      (list 2) 0 -1)

(structure->constructor (make-pt 5 7))	; => (make-pt 5 7)
